A minor 2.0 magnitude submarine earthquake struck at 3:48 a.m. on March 13, 2026, about 20.5 miles south-southeast of McClellanville, S.C., at coordinates 32.796° N, 79.389° W, with a 6.5-mile depth. Detected by the U.S. Geological Survey, it caused no reported damage or felt shaking in the Lowcountry.
Fault Background
The event occurred on the Helena Banks Fault Zone, running parallel to Charleston County’s coast, linked to Mesozoic rifting during Pangea’s breakup. Discovered in the 1980s by USGS geologist John Behrendt, this strike-slip fault shows rare activity outside the Ring of Fire (90% of global quakes).
Regional Context
One of few offshore quakes in the area, it underscores South Carolina’s seismic potential despite low risk—historic faults like this tie to ancient tectonics, not plate boundaries. No tsunami threat; monitor USGS for aftershocks.
